Many common problems such as fatigue, depression and difficulty losing weight can be due to low thyroid, however, many people, especially women, are not getting the treatment that would be of great benefit. This is because severely low thyroid levels are often not picked up by the standard TSH, T4, and T 3 testing, which is the only testing done about 90% of the time.
New studies indicate, however, that the ratio of active thyroid hormone, T 3 must be determined to accurately determine an individual’s true thyroid levels. This can often reveal a problem of hypothyroidism even though the standard tests are normal. This test is rarely done, however, even though this is the most important determinate of thyroid function. Individuals on thyroid hormone also often receive improper doses, usually too low, when the TSH is used for dosing.
There is mounting evidence that hypothyroidism is present in the majority of and possibly all fatigued patients. The problem is that standard blood testing that consists of TSH, T4 and T 3 does not detect it. Thus, many patients are erroneously told over and over that their thyroid levels are fine. TSH is secreted by the pituitary in the brain, telling the thyroid to secrete T4, which is not the active thyroid hormone. T4 must then be converted in the body to the active thyroid hormone T 3. When T4 and T 3 levels drop, the TSH should increase indicating hypothyroidism. This is the standard way to diagnose hypothyroidism. There are, however, many things that result in hypothyroidism but are not diagnosed using the standard TSH and T4 and T 3 testing. This method misses thyroid problems with patients 90% of the time.
Pituitary dysfunction from a variety of causes, including viruses, bacteria, stress, yeast, inflammation, toxins, pesticides, plastics and mitochondria dysfunction. This results in low normal TSH levels along with low normal T4 and T 3 levels.
In addition, many patients do not adequately convert T4 to the active T 3, resulting in low levels of active thyroid hormone and suffer from low thyroid despite having a normal TSH. There is another problem in that T4 cannot only be converted to T 3, but it can also be converted to reverse T 3, which is inactive and blocks the thyroid receptor. There is an evolutionary enzyme that increases the T4 to reverse T 3 in times of stress and illness. This worked well for our ancestors because in times of famine it allowed those who had this enzyme to survive. Low thyroid not only results in undesirable symptoms, but it also increases the risk of heart disease and cancer.